摘要
采用烧结法提取粉煤灰中氧化铝,考察了烧结剂种类、烧结剂协同作用、烧结剂用量、烧结温度及烧结时间等因素对粉煤灰烧结熟料中氧化铝溶出率的影响.试验结果表明:与碳酸钠和氧化钙相比,在较低温度下氢氧化钠能溶出粉煤灰中绝大部分氧化铝;适量的氧化钙能促进氢氧化钠溶出粉煤灰中的氧化铝;氢氧化钠和氧化钙的混合物与粉煤灰进行烧结,烧结效果更好;碱比、钙比、烧结温度和烧结时间等因素对粉煤灰烧结过程影响比较大;通过正交试验得知各因素对粉煤灰烧结熟料中氧化铝溶出率的影响从大到小的顺序为钙比、烧结时间、碱比、烧结温度;当碱比为2∶1、钙比为0.5∶1.0、烧结温度为700℃、烧结时间为30 min时,粉煤灰中氧化铝溶出率达到76.20%.
Utilize sintering method to extract alumina from coal ashes. The effects of sintering flux categories, sintering flux cooperation, sintering flux dosage, temperature and time on the leaching ratio of alumina from coal ashes was studied. The results show that sodium hydroxide can extract the most alumina from coal ashes than natronite and lime at lower temperature, and the leaching ratio of alumina is higher when sintered coal ashes with the mixture of sodium hydroxide and lime, and proper quantities lime can accelerate sodium hydroxide to leach the alumina from coal ashes. The factors of sintering process such as alkali ratio, calcium ratio, sintering temperature, sintering time have great impact on the leaching ratio of alumina in coal ashes. These influencing factors was investigated by orthogonal experiment. The influence order from big to small of above four factors is calcium ratio, sintering time, alkali ratio, sintering temperatures. When alkali ratio is 2： 1, calcium ratio is 0. 5： 1.0, sintering temperatures is 700 ℃ and sintering time is 30 min, the leaching ratio of alumina reached to 76.20% in coal ashes.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2009年第1期105-110,共6页
Journal of China Coal Society
关键词
粉煤灰
氧化铝
烧结
溶出
coal ashes
alumina
sintering
leaching
